000
FXUS62 KRAH 010150
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
950 PM EDT FRI JUL 31 2015
.SYNOPSIS...A COLD FRONT WILL WAVER OVER THE COASTAL PLAIN OF NORTH
CAROLINA THROUGH THE WEEKEND. WEAK HIGH PRESSURE WILL EXTEND INTO
THE PIEDMONT THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM FRIDAY...
THE ISOLD SHOWERS OVER FAR SOUTHERN SCOTLAND CO WILL DISSIPATE OVER
THE NEXT HOUR...LEAVING THE REST OF THE NIGHT CLEAR TO PARTLY CLOUDY
ACROSS THE AREA. FORECAST SOUNDINGS AND MOS GUID STILL SUGGEST THAT
A FEW PATCHES OF LIGHT FOG ARE POSSIBLE ACROSS OUR CENTRAL AND
SOUTHERN COASTAL PLAIN AREAS...BUT FARTHER WEST AND NORTH...LOWER
DEWPOINTS WILL PRECLUDE THE RISK FOR SUCH FOG. THE COMBINATION OF
MAINLY CLEAR SKIES...LIGHT WINDS AND LOWER DEWPOINTS WILL HELP
RESULT IN LOWS IN THE LOW-MID 60S ACROSS OUR NW AND TRIAD ZONES...A
LITTLE COOLER THAN WE`VE SEEN THE PAST SEVERAL WEEKS. FARTHER EAST
WHERE THE DEWPOINTS ARE A LITTLE HIGHER AND A FEW MORE CLOUDS...LOWS
WILL BE IN THE 67-72 RANGE...WARMEST EAST.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 325 PM FRIDAY...
UPPER AIR PATTERN WILL FEATURE AN UPPER LEVEL RIDGE CENTERED OVER
THE SOUTHERN ROCKIES/FOUR CORNERS AREA...EXTENDING INTO THE PACIFIC
NW WHILE A BROAD L/W TROUGH COVERS THE UPPER MID WEST EASTWARD TO
NEW ENGLAND. THE L/W TROUGH WILL UNDERGO SOME MINOR AMPLIFICATION
THANKS TO A SERIES OF S/W ROTATING AROUND THE HUDSON BAY UPPER LOW.
THIS PATTERN WILL SUPPORT WEST-NW FLOW OVER CENTRAL NC. THIS SET-UP
USUALLY RESULTS IN A DRY WEATHER PATTERN AND LITTLE IN THE MANNER OF
MOISTURE ADVECTION. THE STALLED SFC FRONT IMMEDIATELY TO OUR SE WILL
MOVE LITTLE THROUGH THE WEEKEND...LIKELY WAVERING A FEW TENS OF
MILES. THIS FEATURE WILL BE THE FOCUS FOR ISOLATED-SCATTERED
AFTERNOON-EVENING CONVECTION EACH DAY. THUS...EXPECT A SLIGHT CHANCE
POP FOR AREAS ALONG AND EAST OF A KFAY-KGSB LINE. OVER THE
PIEDMONT...EXPECT DRY WEATHER THROUGH THE WEEKEND.
AFTERNOON THICKNESS AVERAGE A FEW METERS ABOVE NORMAL (1428-1435).
THIS SUPPORTS MAX TEMPS IN THE 90-95 DEGREE RANGE. LOW LEVEL FLOW
WILL REMAIN NLY THROUGH EARLY SUNDAY. THIS FLOW WILL USHER/MAINTAIN
A RELATIVELY DRY NEAR SURFACE AIR MASS...YIELDING SFC DEWPOINTS IN
THE 50S-NEAR 60 IN THE PIEDMONT...AND 60-65 OVER THE COASTAL PLAIN
AND SANDHILLS. SO...WHILE AFTERNOON TEMPS WILL BE HOT...THE DRIER
NEAR SURFACE AIR MASS SHOULD HOPEFULLY MAKE THE HEAT A LITTLE MORE
TOLERABLE.
MIN TEMPS SATURDAY NIGHT LOW-MID 60S PIEDMONT TO THE UPPER
60S/AROUND 70 EAST-SE...AND 65-70 NW-LOWER 70S SE SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 245 PM FRIDAY...
THE LATEST 12Z MODEL GUIDANCE IS IN RELATIVELY GOOD AGREEMENT
W/REGARD TO THE EVOLUTION OF THE UPPER LEVEL PATTERN NEXT WEEK. THE
DEEP UPPER LEVEL RIDGE CURRENTLY CENTERED OVER THE WESTERN CONUS
/INTERMOUNTAIN WEST/ WILL GRADUALLY SHIFT EASTWARD TO THE ROCKIES BY
THE MIDDLE OF NEXT WEEK...AND AS THE RIDGE AXIS SHIFTS EAST...A MORE
ACTIVE /ENERGETIC/ PATTERN OF NORTHWEST FLOW ALOFT WILL DEVELOP
DOWNSTREAM OVER THE OH VALLEY/MID-ATLANTIC. FROM A PATTERN
RECOGNITION STANDPOINT...ONE WOULD EXPECT ABOVE NORMAL TEMPERATURES
(MID 90S) AND BELOW NORMAL CHANCES FOR CONVECTION TO PERSIST THROUGH
EARLY NEXT WEEK...TRANSITIONING TO NEAR NORMAL TEMPERATURES AND
AT/ABOVE NORMAL CHANCES FOR CONVECTION BY MID/LATE NEXT WEEK. GIVEN
THAT ENHANCED CONVECTIVE COVERAGE/TIMING WILL BE HIGHLY SENSITIVE TO
THE PRECISE EVOLUTION OF SMALL AMPLITUDE WAVES...UPSTREAM CONVECTION
(I.E. MCS ACTIVITY)...AND/OR CONVECTIVE REMNANTS (I.E. OUTFLOW/
MCV`S)...IT IS DIFFICULT IF NOT IMPOSSIBLE TO DETERMINE FORECAST
SPECIFICS (CONVECTIVE TIMING/COVERAGE/INTENSITY) MID TO LATE NEXT
WEEK. GIVEN THAT STRONGER DEEP LAYER SHEAR AND STEEPER MID-LEVEL
LAPSE RATES (I.E. MODIFIED EML) ARE MORE LIKELY TO BE PRESENT IN A
SYNOPTIC PATTERN CHARACTERIZED BY NW FLOW ALOFT...AN ENHANCED
POTENTIAL FOR SEVERE THUNDERSTORMS MAY BE PRESENT AT SOME POINT IN
THE WED-FRI TIME FRAME...PRIMARILY IF DIURNAL TIMING IS FAVORABLE
W/REGARD TO APPROACHING SHORTWAVE ENERGY. -VINCENT
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 734 PM FRIDAY...
VFR CONDITIONS ARE LIKELY ACROSS THE AREA DURING THE 24 HOUR PERIOD.
THERE IS THE POTENTIAL FOR MVFR FOG AT KFAY AND KRWI EARLY SATURDAY
MORNING WHERE MOISTURE IS HIGHER IN CLOSER PROXIMITY TO THE SURFACE
BOUNDARY NEAR THE COAST. ANY FOG WILL DISSIPATE BY 12Z. WINDS WILL
REMAIN LIGHT AND NORTHWESTERLY... LIKELY BECOMING CALM FOR A PERIOD
AT MOST LOCATIONS OVERNIGHT.
VFR CONDITIONS WILL PREVAIL THROUGH MOST OF THE UPCOMING WEEK. THERE
WILL BE AN INCREASE IN THE POTENTIAL FOR EARLY MORNING FOG AND LOW
CLOUDS AS THE LOWER LEVELS OF THE ATMOSPHERE BECOME INCREASINGLY
MOIST...AS WELL AS A THREAT FOR SCATTERED CONVECTION IN THE
AFTERNOON AND EARLY EVENING HOURS...ESPECIALLY BEYOND MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...RAH
SHORT TERM...WSS
LONG TERM...VINCENT
AVIATION...30/WSS